Study Finds CBD Reduces Both Acute and Inflammatory Pain, Including in Opioid-Dependent Subjects

Research published in the Journal of Psychiatric Research finds that cannabidiol (CBD) can significantly reduce both acute and inflammatory pain, including in subjects with morphine dependence. Researchers from Shahid Beheshti University of Medical Sciences and the Iranian Academy of Medical Sciences examined how CBD affected pain responses in morphine-dependent and non-dependent rats. Chronic morphine use is known to cause tolerance and dependence, often complicating long-term pain treatment and reducing the effectiveness of opioid medications.

In the study, 84 male rats were divided into dependent and non-dependent groups. Morphine dependence was induced over 14 days using escalating oral doses. The animals were then subjected to a formalin test, a well-established model that triggers a two-phase pain response: an early acute phase and a later inflammatory phase.

CBD was administered directly into the brain at varying doses prior to testing. The formalin injection produced clear biphasic pain responses, validating the model. While morphine dependence alone did not significantly alter baseline pain sensitivity, CBD led to a statistically significant and dose-dependent reduction in pain behaviors during both phases of the test. The strongest and most consistent effects were observed at the 100 μg and 200 μg doses.

Importantly, CBD’s pain-relieving effects were comparable in both morphine-dependent and non-dependent animals, suggesting that opioid exposure did not diminish its efficacy. Additional open-field testing showed no significant differences in locomotor activity, indicating that the observed pain reduction was not due to sedation or impaired movement.

The researchers conclude that CBD may offer a promising non-opioid option for managing pain, including in individuals with opioid dependence, without compromising motor function.